# A081663 (b-file synthesized from sequence entry) 0 1 1 3 2 9 3 25 4 66 5 169 6 425 7 1058 8 2621 9 6485 10 16066 11 39921 12 99601 13 249666 14 628917 15 1592029 16 4048866 17 10341577 18 26517113 19 68226722 20 176065901 21 455514533 22 1181040514 23 3067684065 24 7980068641 25 20784441474 26 54188706405 27 141395801773